The present invention relates generally to internal combustion engines with an auxiliary combustion chamber in each cylinder, and more particularly to a stratified-charge reciprocating internal combustion engine with an auxiliary combustion chamber in each cylinder.
In recent years, there have been proposed and developed various direct-injection spark-ignition reciprocating internal combustion engines with an auxiliary combustion chamber in each cylinder. A Published Japanese Patent Application No. H6(1994)-17710 shows such a direct-injection spark-ignition reciprocating internal combustion engine with an auxiliary combustion chamber in each cylinder. In this engine, a cylinder head includes a cavity serving as an auxiliary combustion chamber in conjunction with a piston crown. A spark plug is provided in the auxiliary combustion chamber. Fuel is supplied into the auxiliary combustion chamber through an auxiliary fuel gas supply port. The auxiliary fuel gas supply port is connected to a fuel supply via a pressure control valve and a supply control valve. The pressure control valve, the supply control valve, and the auxiliary fuel gas supply port serve as a fuel injection valve. In the auxiliary combustion chamber, intake air and fuel are mixed to form a rich air-fuel mixture. The rich air-fuel mixture formed in the auxiliary combustion chamber is ignited by the spark plug, so that a combustion flame propagates within a main combustion chamber next to the auxiliary combustion chamber. Thus, the engine allows overall lean air-fuel mixture to burn, resulting in a decrease in fuel consumption.